We thank Diana Hincapie, Rafael Santos, and Camilo Morales for excellent research assistance, and Roberto Alvarez, Mary Amiti, Orazio Attanasio, Sebastian Edwards, Ricardo Hausmann, Larry Kleinman, Ralf Martin, Alejandro Micco, Nina Pavcnik, Carmen Pages, Dani Rodrik, Chad Syverson and John van Reenen as well as participants at numerous seminars and conferences. Support was provided by NSF Grant SES-0617816, the Tinker Foundation, the IDB, and a GEAR grant from the University of Houston. We are also grateful to the National Planning Department for providing data on tariffs, and to DANE for access to the Manufacturing Survey and advice about its use. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research.